A pair of Brevan Howard Asset Management traders have left the firm in the wake of losses in its flagship hedge fund.

Wayne Leslie and Jason Feasey were credit traders at Brevan Howard, and bring to at least a dozen the number of traders who have left the firm since the end of May, Bloomberg News reports. In June, Brevan Howard's Master Fund lost 2.9%, its worst month in almost five years, and fell another 0.9% last month.

Leslie's exit comes less than a year after he joined the hedge fund from Goldman Sachs, where he was a managing director in European investment-grade credit trading. Feasey, a structured-credit specialist, had been with Brevan Howard since 2011, when he joined from Bank of America.